SAFE public projects git trees. - safe/jmp/linux-2.6/blob - fs/cifs/cifsencrypt.c

   1 /*
   2  *   fs/cifs/cifsencrypt.c
   3  *
   4  *   Copyright (C) International Business Machines  Corp., 2005,2006
   5  *   Author(s): Steve French (sfrench@us.ibm.com)
   6  *
   7  *   This library is free software; you can redistribute it and/or modify
   8  *   it under the terms of the GNU Lesser General Public License as published
   9  *   by the Free Software Foundation; either version 2.1 of the License, or
  10  *   (at your option) any later version.
  11  *
  12  *   This library is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
  15  *   the GNU Lesser General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU Lesser General Public License
  18  *   along with this library; if not, write to the Free Software
  19  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/fs.h>
  23 #include "cifspdu.h"
  24 #include "cifsglob.h"
  25 #include "cifs_debug.h"
  26 #include "md5.h"
  27 #include "cifs_unicode.h"
  28 #include "cifsproto.h"
  29 #include <linux/ctype.h>
  30
  31 /* Calculate and return the CIFS signature based on the mac key and the smb pdu */
  32 /* the 16 byte signature must be allocated by the caller  */
  33 /* Note we only use the 1st eight bytes */
  34 /* Note that the smb header signature field on input contains the
  35         sequence number before this function is called */
  36
  37 extern void mdfour(unsigned char *out, unsigned char *in, int n);
  38 extern void E_md4hash(const unsigned char *passwd, unsigned char *p16);
  39 extern void SMBencrypt(unsigned char *passwd, unsigned char *c8,
  40                        unsigned char *p24);
  41
  42 static int cifs_calculate_signature(const struct smb_hdr * cifs_pdu,
  43                                     const char * key, char * signature)
  44 {
  45         struct  MD5Context context;
  46
  47         if((cifs_pdu == NULL) || (signature == NULL))
  48                 return -EINVAL;
  49
  50         MD5Init(&context);
  51         MD5Update(&context,key,CIFS_SESS_KEY_SIZE+16);
  52         MD5Update(&context,cifs_pdu->Protocol,cifs_pdu->smb_buf_length);
  53         MD5Final(signature,&context);
  54         return 0;
  55 }
  56
  57 int cifs_sign_smb(struct smb_hdr * cifs_pdu, struct TCP_Server_Info * server,
  58         __u32 * pexpected_response_sequence_number)
  59 {
  60         int rc = 0;
  61         char smb_signature[20];
  62
  63         if((cifs_pdu == NULL) || (server == NULL))
  64                 return -EINVAL;
  65
  66         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
  67                 return rc;
  68
  69         spin_lock(&GlobalMid_Lock);
  70         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(server->sequence_number);
  71         cifs_pdu->Signature.Sequence.Reserved = 0;
  72
  73         *pexpected_response_sequence_number = server->sequence_number++;
  74         server->sequence_number++;
  75         spin_unlock(&GlobalMid_Lock);
  76
  77         rc = cifs_calculate_signature(cifs_pdu, server->mac_signing_key,smb_signature);
  78         if(rc)
  79                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
  80         else
  81                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
  82
  83         return rc;
  84 }
  85
  86 static int cifs_calc_signature2(const struct kvec * iov, int n_vec,
  87                                 const char * key, char * signature)
  88 {
  89         struct  MD5Context context;
  90         int i;
  91
  92         if((iov == NULL) || (signature == NULL))
  93                 return -EINVAL;
  94
  95         MD5Init(&context);
  96         MD5Update(&context,key,CIFS_SESS_KEY_SIZE+16);
  97         for(i=0;i<n_vec;i++) {
  98                 if(iov[i].iov_base == NULL) {
  99                         cERROR(1,("null iovec entry"));
 100                         return -EIO;
 101                 } else if(iov[i].iov_len == 0)
 102                         break; /* bail out if we are sent nothing to sign */
 103                 /* The first entry includes a length field (which does not get
 104                    signed that occupies the first 4 bytes before the header */
 105                 if(i==0) {
 106                         if (iov[0].iov_len <= 8 ) /* cmd field at offset 9 */
 107                                 break; /* nothing to sign or corrupt header */
 108                         MD5Update(&context,iov[0].iov_base+4, iov[0].iov_len-4);
 109                 } else
 110                         MD5Update(&context,iov[i].iov_base, iov[i].iov_len);
 111         }
 112
 113         MD5Final(signature,&context);
 114
 115         return 0;
 116 }
 117
 118
 119 int cifs_sign_smb2(struct kvec * iov, int n_vec, struct TCP_Server_Info *server,
 120                    __u32 * pexpected_response_sequence_number)
 121 {
 122         int rc = 0;
 123         char smb_signature[20];
 124         struct smb_hdr * cifs_pdu = iov[0].iov_base;
 125
 126         if((cifs_pdu == NULL) || (server == NULL))
 127                 return -EINVAL;
 128
 129         if((cifs_pdu->Flags2 & SMBFLG2_SECURITY_SIGNATURE) == 0)
 130                 return rc;
 131
 132         spin_lock(&GlobalMid_Lock);
 133         cifs_pdu->Signature.Sequence.SequenceNumber =
 134                                 cpu_to_le32(server->sequence_number);
 135         cifs_pdu->Signature.Sequence.Reserved = 0;
 136
 137         *pexpected_response_sequence_number = server->sequence_number++;
 138         server->sequence_number++;
 139         spin_unlock(&GlobalMid_Lock);
 140
 141         rc = cifs_calc_signature2(iov, n_vec, server->mac_signing_key,
 142                                       smb_signature);
 143         if(rc)
 144                 memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 145         else
 146                 memcpy(cifs_pdu->Signature.SecuritySignature, smb_signature, 8);
 147
 148         return rc;
 149
 150 }
 151
 152 int cifs_verify_signature(struct smb_hdr * cifs_pdu, const char * mac_key,
 153         __u32 expected_sequence_number)
 154 {
 155         unsigned int rc;
 156         char server_response_sig[8];
 157         char what_we_think_sig_should_be[20];
 158
 159         if((cifs_pdu == NULL) || (mac_key == NULL))
 160                 return -EINVAL;
 161
 162         if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
 163                 return 0;
 164
 165         if (cifs_pdu->Command == SMB_COM_LOCKING_ANDX) {
 166                 struct smb_com_lock_req * pSMB = (struct smb_com_lock_req *)cifs_pdu;
 167             if(pSMB->LockType & LOCKING_ANDX_OPLOCK_RELEASE)
 168                         return 0;
 169         }
 170
 171         /* BB what if signatures are supposed to be on for session but server does not
 172                 send one? BB */
 173
 174         /* Do not need to verify session setups with signature "BSRSPYL "  */
 175         if(memcmp(cifs_pdu->Signature.SecuritySignature,"BSRSPYL ",8)==0)
 176                 cFYI(1,("dummy signature received for smb command 0x%x",cifs_pdu->Command));
 177
 178         /* save off the origiginal signature so we can modify the smb and check
 179                 its signature against what the server sent */
 180         memcpy(server_response_sig,cifs_pdu->Signature.SecuritySignature,8);
 181
 182         cifs_pdu->Signature.Sequence.SequenceNumber = cpu_to_le32(expected_sequence_number);
 183         cifs_pdu->Signature.Sequence.Reserved = 0;
 184
 185         rc = cifs_calculate_signature(cifs_pdu, mac_key,
 186                 what_we_think_sig_should_be);
 187
 188         if(rc)
 189                 return rc;
 190
 191
 192 /*      cifs_dump_mem("what we think it should be: ",what_we_think_sig_should_be,16); */
 193
 194         if(memcmp(server_response_sig, what_we_think_sig_should_be, 8))
 195                 return -EACCES;
 196         else
 197                 return 0;
 198
 199 }
 200
 201 /* We fill in key by putting in 40 byte array which was allocated by caller */
 202 int cifs_calculate_mac_key(char * key, const char * rn, const char * password)
 203 {
 204         char temp_key[16];
 205         if ((key == NULL) || (rn == NULL))
 206                 return -EINVAL;
 207
 208         E_md4hash(password, temp_key);
 209         mdfour(key,temp_key,16);
 210         memcpy(key+16,rn, CIFS_SESS_KEY_SIZE);
 211         return 0;
 212 }
 213
 214 int CalcNTLMv2_partial_mac_key(struct cifsSesInfo * ses, struct nls_table * nls_info)
 215 {
 216         char temp_hash[16];
 217         struct HMACMD5Context ctx;
 218         char * ucase_buf;
 219         __le16 * unicode_buf;
 220         unsigned int i,user_name_len,dom_name_len;
 221
 222         if(ses == NULL)
 223                 return -EINVAL;
 224
 225         E_md4hash(ses->password, temp_hash);
 226
 227         hmac_md5_init_limK_to_64(temp_hash, 16, &ctx);
 228         user_name_len = strlen(ses->userName);
 229         if(user_name_len > MAX_USERNAME_SIZE)
 230                 return -EINVAL;
 231         if(ses->domainName == NULL)
 232                 return -EINVAL; /* BB should we use CIFS_LINUX_DOM */
 233         dom_name_len = strlen(ses->domainName);
 234         if(dom_name_len > MAX_USERNAME_SIZE)
 235                 return -EINVAL;
 236
 237         ucase_buf = kmalloc((MAX_USERNAME_SIZE+1), GFP_KERNEL);
 238         if(ucase_buf == NULL)
 239                 return -ENOMEM;
 240         unicode_buf = kmalloc((MAX_USERNAME_SIZE+1)*4, GFP_KERNEL);
 241         if(unicode_buf == NULL) {
 242                 kfree(ucase_buf);
 243                 return -ENOMEM;
 244         }
 245
 246         for(i=0;i<user_name_len;i++)
 247                 ucase_buf[i] = nls_info->charset2upper[(int)ses->userName[i]];
 248         ucase_buf[i] = 0;
 249         user_name_len = cifs_strtoUCS(unicode_buf, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
 250         unicode_buf[user_name_len] = 0;
 251         user_name_len++;
 252
 253         for(i=0;i<dom_name_len;i++)
 254                 ucase_buf[i] = nls_info->charset2upper[(int)ses->domainName[i]];
 255         ucase_buf[i] = 0;
 256         dom_name_len = cifs_strtoUCS(unicode_buf+user_name_len, ucase_buf, MAX_USERNAME_SIZE*2, nls_info);
 257
 258         unicode_buf[user_name_len + dom_name_len] = 0;
 259         hmac_md5_update((const unsigned char *) unicode_buf,
 260                 (user_name_len+dom_name_len)*2,&ctx);
 261
 262         hmac_md5_final(ses->server->mac_signing_key,&ctx);
 263         kfree(ucase_buf);
 264         kfree(unicode_buf);
 265         return 0;
 266 }
 267
 268 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 269 void calc_lanman_hash(struct cifsSesInfo * ses, char * lnm_session_key)
 270 {
 271         int i;
 272         char password_with_pad[CIFS_ENCPWD_SIZE];
 273
 274         if(ses->server == NULL)
 275                 return;
 276
 277         memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
 278         strncpy(password_with_pad, ses->password, CIFS_ENCPWD_SIZE);
 279
 280         if((ses->server->secMode & SECMODE_PW_ENCRYPT) == 0)
 281                 if(extended_security & CIFSSEC_MAY_PLNTXT) {
 282                         memcpy(lnm_session_key, password_with_pad, CIFS_ENCPWD_SIZE);
 283                         return;
 284                 }
 285
 286         /* calculate old style session key */
 287         /* calling toupper is less broken than repeatedly
 288         calling nls_toupper would be since that will never
 289         work for UTF8, but neither handles multibyte code pages
 290         but the only alternative would be converting to UCS-16 (Unicode)
 291         (using a routine something like UniStrupr) then
 292         uppercasing and then converting back from Unicode - which
 293         would only worth doing it if we knew it were utf8. Basically
 294         utf8 and other multibyte codepages each need their own strupper
 295         function since a byte at a time will ont work. */
 296
 297         for(i = 0; i < CIFS_ENCPWD_SIZE; i++) {
 298                 password_with_pad[i] = toupper(password_with_pad[i]);
 299         }
 300
 301         SMBencrypt(password_with_pad, ses->server->cryptKey, lnm_session_key);
 302         /* clear password before we return/free memory */
 303         memset(password_with_pad, 0, CIFS_ENCPWD_SIZE);
 304 }
 305 #endif /* CIFS_WEAK_PW_HASH */
 306
 307 void CalcNTLMv2_response(const struct cifsSesInfo * ses,char * v2_session_response)
 308 {
 309         struct HMACMD5Context context;
 310         memcpy(v2_session_response + 8, ses->server->cryptKey,8);
 311         /* gen_blob(v2_session_response + 16); */
 312         hmac_md5_init_limK_to_64(ses->server->mac_signing_key, 16, &context);
 313
 314         hmac_md5_update(ses->server->cryptKey,8,&context);
 315 /*      hmac_md5_update(v2_session_response+16)client thing,8,&context); */ /* BB fix */
 316
 317         hmac_md5_final(v2_session_response,&context);
 318         cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); /* BB removeme BB */
 319 }